Yasuko Hanaoka is a divorced, single mother who thought she had finally escaped her abusive ex-husband Togashi. When he shows up one day to extort money from her, threatening both her and her teenaged daughter Misato, the situation quickly escalates into violence and Togashi ends up dead on her apartment floor. Overhearing the commotion, Yasuko’s next door neighbor, middle-aged high school mathematics teacher Ishigami, offers his help, disposing not only of the body but plotting the cover-up step-by-step.

When the body turns up and is identified, Detective Kusanagi draws the case and Yasuko comes under suspicion. Kusanagi is unable to find any obvious holes in Yasuko’s manufactured alibi and yet is still sure that there’s something wrong. Kusanagi brings in Dr. Manabu Yukawa, a physicist and college friend who frequently consults with the police. Yukawa, known to the police by the nickname Professor Galileo, went to college with Ishigami. After meeting up with him again, Yukawa is convinced that Ishigami had something to do with the murder. What ensues is a high level battle of wits, as Ishigami tries to protect Yasuko by outmaneuvering and outthinking Yukawa, who faces his most clever and determined opponent yet.

Wow. This. Book. Is. Brilliant.

Okay, so the reason I actually discovered this book was because someone in K-pop was reading it and I was curious to find out about his reading tastes. LOL @ my shallow reasons XDD But I regret nothing now!!!

The Devotion of Suspect X begins with an accidental murder. Yasuko Hanaoka is your normal lady trying to live a normal life with her daughter. Except she’s got this no-good ex-husband, Togashi, who shows up and tries to get money from her. She tries to refuse, he threatens her and eventually he ends up dead on the floor of her apartment. Her neighbor, Ishigami (who has a sort of crush on her), overhears the commotion and decides to help her get rid of the body and cover up the entire thing.

Okay, that sounds pretty normal for a mystery/crime novel, I guess. Except Ishigami is a mathematical genius who uses logic to create a plan that is super brilliant, and one I don’t really want to talk about because I might end up saying something spoilery. Nevertheless, it is amazing to read the book and unravel the pieces of the puzzle one by one.

It’s pretty interesting how math is a factor in this…I hate math but the way it is explained in this book is simple and easy to understood (kudos to you author and translator!!). I’ve always said you don’t really need ~complicated math in real life but…Ishigami treats the murder like a mathematical equation and just… nah, nope not gonna say anything because

But anyway. I was surprised at how fast I read through this book, even with the math equations and explanations. Because normally math makes me fall asleep or run away. lmao The story just sucked me in, waiting in anticipation and dread for them to discover who the killer was. Because I really, really didn’t want the police to find out since Yasuko, well, was justified in her reasons and I didn’t want her life (and her daughter’s) to be ruined :c

The plot twist totally killed me because I did not see it happeniiiiiing AT ALL, which was pretty awesome for me because…this is a crime novel where you know from the start who the killer is. It’s just..how everything was done being slowly explained throughout the book that’s so enthralling…and just when I thought I knew everything and decided to just wait for the inevitable (because well, shouldn’t all crime novels end with the crimes being solved lol), the author came and punched me in the face while cackling and saying, “Hah! Surprise!!”

And that left me stunned and unable to sleep for a while, despite the fact that I stayed up late to finish reading. lels